credit to zewaka for the idea of using underlays
turns the lighting object movables that were unnecessary and increased maptick into a datum which then applies and removes an underlay in update(). also applies a lot of general lighting clean ups (mostly using as anything in loops and fixing single letter var names).
multiz is a little different by necessity, now only the bottom turf's lighting matters in the brightness of the top turf unlike master where the bottom turf's lighting object is hidden from the vis_contents of the top turf. there are still some kinks to iron out here though, since currently objects suspended in openspace (like tram platforms) look bad and glass floors look bad too
only thing i have left to do is make multiz work (well)
UPDATE: multiz now appears the same as far as i can tell, its possible there are other situations in which its different but datum mats work and it automatically updates if the turf below changes. now i just need to make the system less finnicky if at all possible (and possibly merge managed_turf_vis_content with managed_overlays maybe?)
new update: its basically equivalent to normal multiz as far as i can tell (visually at least, in the circumstances ive tested so far)
NEW NEW UPDATE: turfs no longer have the VIS_HIDE vis_flag and multiz works without stacking the lighting from the floor below! so this shouldnt have any overt drawbacks to master anymore
1 needless movable per tile is terrible for maptick. this is probably a larger improvement than my emissive blocker change in terms of maptick. im guessing we'd get around 0.6 average maptick per player after this where currently we get 0.85 or so
Edit: according to lemon, sybil reached 0.71 maptick per person when tm'd with this
if this is a big enough improvement i might finally be able to get rid of the Gone discord avatar
Rather then remove the light from all tiles, then re-add the light to all tiles, we just go thru each tile and diff the light level from the last value we added to it. (since this is tracked)
This cut the proc calls for updating lights in half.
Lighting objects now default to full brite rather then full dark so shuttles aren't as immersion breaking when they transit.
Made lighting more agressive about clearing empty lists.
* Revert "Lighting micro optimizations and fixes (#24939)"
This reverts commit 78bbbfe20a.
* vg refactor stage 1
* Fix runtime in get_turf_pixel
* fix lighting on turfs
* Fix certain things reading light levels wrong.
* Made SS faster/better by making it split its tick allotment up between it's 3 tasks
* istypeless loops @pjb3005
/proc/typed_loop 6.826 6.830 6.858 190761
/proc/typeless_loop 5.582 5.586 5.620 190435
* lazy init lists
